The present invention relates to a fabric for ink-jet recording and a process for manufacturing the same, and more particularly to a sufficiently flame-retardant fabric for ink-jet recording with an ink accepting layer on its one side at least, the ink acceptability of which is the same as that of its non-flame-retardant counterpart.
In recent years, large-sized ink jet equipment intended for ink-jet printing onto paper, resin sheet and other similar substrates have been developed. Such ink jet equipment provides for manufacturing of large-size products printed with deep- and brilliant-shade full color, only possible to manufacture with ink-jet printing, such as hanging screens and banners having lengths exceeding several meters. However, such hanging screens and banners manufactured using paper, resin sheet and other similar material as their substrates are not necessarily resistant to bending (and are thus liable to crease), while presenting problems associated with strength such as durability.
As a substitute for such ink-jet printing substrates, fiber fabric which is light in weight and highly resistant to bending, as well as excellent in durability and tear strength, has attracted attention. As its characteristic feature, however, fabric has such large surface irregularities compared to those of paper or resin sheet (the surface of which is smooth) that particles of coloring material in the ink applied onto the fabric are liable to diffuse over and into it, resulting in its poor surface shade depth. This makes it difficult for ink-jet printing onto fabric to achieve such a brilliant color image as achieved in the case with paper or resin sheet.
On the other hand, fabric, which is generally liable to catch fire or inflammable, is often required to be more flame retardant if used as a substrate of a hanging screen or banner for indoor use than otherwise. To meet such requirements in the field of ink-jet printing, one prior proposal is to prepare fabric with an ink accepting layer which is flame retarded, which, however, has proved to result extremely difficult representation of a highly deep and brilliant shade color image onto the fabric. This is also the case when the ink to be applied onto such fabric is of a type prepared with its water insoluble coloring matter dispersed in water. Many techniques have been disclosed to provide effective methods for ink-jet printing of paper and resin sheet with highly deep and brilliant shade color representation as well as flame retardancy. However, it is impossible to apply these techniques to fabric, which has surface irregularities and a peculiar propensity to cause the ink applied to it to bleed (with poor ink dot shape), in the same way as in the case of paper or resin sheet.
Therefore, techniques have also been developed for ink-jet printing on fabric to provide it with both highly deep and brilliant shade color and flame retardancy. According to one such prior technique as disclosed in Japanese Patent JP-A-2000-203148, a synthetic fiber fabric is pretreated to form an ink accepting layer on its one side and a flame-retardant layer on its other side. This technique, however, has the disadvantage that any increase in the amount of ink applied to fabric to enhance the color shade depth on the fabric necessarily requires it to be pretreated with a thicker ink accepting layer, which is not sufficiently flame retardant, causing its printed ink accepting layer side to become insufficiently resistant to heat.
According to another such prior technique as disclosed in Japanese Patent JP-A-2000-303361, a fabric is impregnated with an ink acceptor to form an ink accepting layer on the fabric and then with a flame retarding agent to make it flame retardant as a whole. However, this technique has the disadvantage of necessitating the ink accepting layer formed on fabric to be covered with a subsequently applied flame retardant agent and any dispersant and/or viscosity improver contained in the agent, resulting in deterioration in its ink accepting function that may not otherwise occur. Fabric treated according to the above-mentioned prior technique, especially when printed with ink of water-insoluble coloring matter dispersed in water, fails to yield deep shade and sharp color images.
Therefore, among the prior art disclosures found to deal with fabric for ink-jet recording with an ink accepting layer on its one side to apply solvent-based ink or water-based ink, especially ink of water-insoluble coloring matter dispersed in water, onto the ink accepting layer to represent deep shade and sharp color images, there are none which address the problem of manufacturing a sufficiently flame-retardant fabric for ink-jet recording with an ink accepting layer on its one side, the ink acceptability of which is the same as that of its non-flame-retardant counterpart.
Accordingly, it is an object of the present invention to solve the above-mentioned problems associated with the prior art, thereby providing a sufficiently flame-retardant fabric for ink-jet recording with an ink accepting layer on its one side at least, the ink acceptability (ink holding capability) of which is the same as that of its non-flame-retardant counterpart, allowing it to render highly deep/brilliant shade and sharp color images.
The present invention has successfully solved the above-mentioned prior art problems through its features as described below. One aspect of the present invention provides a flame-retardant fabric for ink-jet recording, consisting of a flame retarded fiber substrate with an ink accepting layer on its one side at least, which is made up of top and bottom sub-layers with a flame retarding agent contained only in the bottom sub-layer.
Another aspect of the present invention provides a flame-retardant fabric for ink-jet recording wherein said flame retarding agent has its active ingredient accounting for 4 to 30% of the entire ink accepting layer by weight.
Still another aspect of the present invention provides a flame-retardant fabric for ink-jet recording, wherein said flame retarding agent is readily soluble or dispersible in water or aqueous solvent.
A further aspect of the present invention provides a flame-retardant fabric for ink-jet recording, wherein said top sub-layer is 3 to 12 xcexcm in thickness.
A still further aspect of the present invention provides a flame-retardant fabric for ink-jet recording, consisting of a flame retarded fiber substrate with an ink accepting layer on its one side at least, which is made up of a top sub-layer 3 to 12 xcexcm in thickness and a bottom sub-layer with a flame retarding agent contained only in the bottom sub-layer, wherein said flame retarding agent has its active ingredient applied to the substrate in an aqueous dispersion, accounting for 4 to 30% of the entire ink accepting layer by weight.
Another aspect of the present invention provides a process for manufacturing a flame-retardant fabric for ink-jet recording, consisting of a flame retarded fiber substrate with an ink accepting layer on its one side at least, by forming said ink accepting layer as two sub-layers in two stepsxe2x80x94first, a bottom sub-layer containing a flame retarding agent and then, a top sub-layer containing no flame retarding agent.
Yet another aspect of the present invention provides a process for manufacturing a flame-retardant fabric for ink-jet recording, consisting of a flame retarded fiber substrate with an ink accepting layer on its one side at least, by forming said ink accepting layer as two sub-layers in two stepsxe2x80x94first, a bottom sub-layer containing a flame retarding agent and then, a top sub-layer 3 to 12 xcexcm in thickness containing no flame retarding agent.
A further aspect of the present invention provides a process for manufacturing a flame-retardant fabric for ink-jet recording, wherein said flame retarding agent has its active ingredient accounting for 4 to 30% of the entire ink accepting layer by weight and is readily soluble or dispersible in water or aqueous solvent.
It is within the scope of the invention to combine two or more of the above features.